path: root/block/blk-settings.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Functions related to setting various queue properties from drivers
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/bio.h>
#include <linux/blk-integrity.h>
#include <linux/pagemap.h>
#include <linux/backing-dev-defs.h>
#include <linux/gcd.h>
#include <linux/lcm.h>
#include <linux/jiffies.h>
#include <linux/gfp.h>
#include <linux/dma-mapping.h>
#include <linux/t10-pi.h>
#include <linux/crc64.h>

#include "blk.h"
#include "blk-rq-qos.h"
#include "blk-wbt.h"

void blk_queue_rq_timeout(struct request_queue *q, unsigned int timeout)
{
	WRITE_ONCE(q->rq_timeout, timeout);
}
EXPORT_SYMBOL_GPL(blk_queue_rq_timeout);

/**
 * blk_set_stacking_limits - set default limits for stacking devices
 * @lim:  the queue_limits structure to reset
 *
 * Prepare queue limits for applying limits from underlying devices using
 * blk_stack_limits().
 */
void blk_set_stacking_limits(struct queue_limits *lim)
{
	memset(lim, 0, sizeof(*lim));
	lim->logical_block_size = SECTOR_SIZE;
	lim->physical_block_size = SECTOR_SIZE;
	lim->io_min = SECTOR_SIZE;
	lim->discard_granularity = SECTOR_SIZE;
	lim->dma_alignment = SECTOR_SIZE - 1;
	lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK;

	/* Inherit limits from component devices */
	lim->max_segments = USHRT_MAX;
	lim->max_discard_segments = USHRT_MAX;
	lim->max_hw_sectors = UINT_MAX;
	lim->max_segment_size = UINT_MAX;
	lim->max_sectors = UINT_MAX;
	lim->max_dev_sectors = UINT_MAX;
	lim->max_write_zeroes_sectors = UINT_MAX;
	lim->max_hw_wzeroes_unmap_sectors = UINT_MAX;
	lim->max_user_wzeroes_unmap_sectors = UINT_MAX;
	lim->max_hw_zone_append_sectors = UINT_MAX;
	lim->max_user_discard_sectors = UINT_MAX;
	lim->atomic_write_hw_max = UINT_MAX;
}
EXPORT_SYMBOL(blk_set_stacking_limits);

void blk_apply_bdi_limits(struct backing_dev_info *bdi,
		struct queue_limits *lim)
{
	u64 io_opt = lim->io_opt;

	/*
	 * For read-ahead of large files to be effective, we need to read ahead
	 * at least twice the optimal I/O size. For rotational devices that do
	 * not report an optimal I/O size (e.g. ATA HDDs), use the maximum I/O
	 * size to avoid falling back to the (rather inefficient) small default
	 * read-ahead size.
	 *
	 * There is no hardware limitation for the read-ahead size and the user
	 * might have increased the read-ahead size through sysfs, so don't ever
	 * decrease it.
	 */
	if (!io_opt && (lim->features & BLK_FEAT_ROTATIONAL))
		io_opt = (u64)lim->max_sectors << SECTOR_SHIFT;

	bdi->ra_pages = max3(bdi->ra_pages,
				io_opt * 2 >> PAGE_SHIFT,
				VM_READAHEAD_PAGES);
	bdi->io_pages = lim->max_sectors >> PAGE_SECTORS_SHIFT;
}

static int blk_validate_zoned_limits(struct queue_limits *lim)
{
	if (!(lim->features & BLK_FEAT_ZONED)) {
		if (WARN_ON_ONCE(lim->max_open_zones) ||
		    WARN_ON_ONCE(lim->max_active_zones) ||
		    WARN_ON_ONCE(lim->zone_write_granularity) ||
		    WARN_ON_ONCE(lim->max_zone_append_sectors))
			return -EINVAL;
		return 0;
	}

	if (WARN_ON_ONCE(!IS_ENABLED(CONFIG_BLK_DEV_ZONED)))
		return -EINVAL;

	/*
	 * Given that active zones include open zones, the maximum number of
	 * open zones cannot be larger than the maximum number of active zones.
	 */
	if (lim->max_active_zones &&
	    lim->max_open_zones > lim->max_active_zones)
		return -EINVAL;

	if (lim->zone_write_granularity < lim->logical_block_size)
		lim->zone_write_granularity = lim->logical_block_size;

	/*
	 * The Zone Append size is limited by the maximum I/O size and the zone
	 * size given that it can't span zones.
	 *
	 * If no max_hw_zone_append_sectors limit is provided, the block layer
	 * will emulated it, else we're also bound by the hardware limit.
	 */
	lim->max_zone_append_sectors =
		min_not_zero(lim->max_hw_zone_append_sectors,
			min(lim->chunk_sectors, lim->max_hw_sectors));
	return 0;
}

/*
 * Maximum size of I/O that needs a block layer integrity buffer.  Limited
 * by the number of intervals for which we can fit the integrity buffer into
 * the buffer size.  Because the buffer is a single segment it is also limited
 * by the maximum segment size.
 */
static inline unsigned int max_integrity_io_size(struct queue_limits *lim)
{
	return min_t(unsigned int, lim->max_segment_size,
		(BLK_INTEGRITY_MAX_SIZE / lim->integrity.metadata_size) <<
			lim->integrity.interval_exp);
}

static int